The memory space of a computer is often composed of random access memories (RAMs) residing on RAM cards which are connected to the data and address busses of the computer. Each RAM has a predetermined address within the memory space and each individual RAM memory location has a specific address within the RAM. In practice, the upper bits of a memory address specify a particular RAM and the lower bits specify a given memory location within that RAM.
In computers which are constructed according to the prior art it is known to specify the location of a RAM within the memory space by physically setting an address on a switch array. A given RAM is enabled when a comparator on the RAM card indicates that an address on the bus is the same as the RAM address on the switch array. In such prior art computers it is necessary for the user to set the specified address of each RAM on the RAM card switch array. The use of such switches introduces the possibility of user error and user-caused damage to the computer.